40. THAMNOPHIS 809 



Tropidonotus sirtalis var. collaris Garman, Mem. Mus. Comp. Zool., 



Vol. XIII, No. 3, 1883, p. 25. 

 Eutttnia collaris Cope. Proc. Am. Philos. See, Vol. XXII, 1884, p. 173; 



Duces, La Naturaleza, Ser. 2, Vol. I, 1888, p. 127, pi. XIII, fig. 



16. 

 Eutania cyrtopsis collaris Cope, Proc. U. S. Nat. Mus., Vol. XIV, 1892, 



p. 657. 

 Eutania aurata Cope, Proc. U. S. Nat. Mus., Vol. XIV, 1892, p. 659 



(type locality, Lake Valley, southern New Mexico). 

 Tropidonotus ordinatus var. eques Boulenger, Cat. Snakes Brit. Mus,, 



Vol. I, 1893, p. 209. 

 Eutcenia eques Cope, Report U. S. Nat. Mus. for 1898, 1900, p. 1049; 



Brown, Proc. Acad. Nat. Sci. Phila., 1901, p. 25; Ditmars, Reptile 



Book, 1907, p. 230, pis. LXVI, fig. 8, LXXI, fig. i. 

 Eutcenia eques collaris Cope, Report U. S. Nat. Mus. for 1898, 1900, 



p. -1051. 

 Eutania eques aurata Cope, Report U. S. Nat. Mus. for 1898, 1900, 



p. 1052. 

 Thamnophis cyrtopsis Stejnecer, Proc. U. S. Nat. Mus., Vol. XXV, 



1902, p. 155. 

 Eutania sirtalis dorsalis Cope, Report U. S. Nat. Mus. for 1898, 1900, 



p. 1076. 

 Thamnophis eques, Ruthven, Bull. Am. Mus. Nat. Hist., Vol. XXIII, 



1907, p. 588; Ruthven, Bull. U. S. Nat. Mus., No. 61, 1908, p. 



158; Stone, Proc. Acad. Nat. Sci. Phila., 191 1, p. 232; Van Den- 

 burgh & Slevin, Proc. Cal. Acad. Sci., Ser. 4, Vol. Ill, p. 419; 



Stejneger & Barbour, Check List N. Amer. Amph. Rept., 1917, 



p. loi; Van Denburgh & Slevin, Proc. Cal. Acad. Sci., Ser. 4, 



Vol. VIII, No. 6, 1918, p. 204. 



Description. — Head distinct from neck, flat-topped with 

 narrow, rounded snout. Temporal regions sometimes 

 swollen in old individuals. Eye moderate. Rostral plate 

 large, bounded behind by internasal, anterior nasal, and first 

 labial plates. Plates on top of head, a pair of internasals, 

 a pair of prefrontals, a frontal, supraocular of each side, 

 and a pair of parietals. Anterior and posterior nasals dis- 

 tinct. One loreal. One or rarely two preoculars. Post- 

 oculars normally three, rarely two or four. Temporals 



